The present invention relates to truck mud flaps and more specifically it relates to automatically retracted mud flaps used on dump trucks. As we all know, mud flaps are required equipment on all trucks to prevent the discharge of pebbles, rocks, dried mud clumps or the like that are lodged between the tires of the truck and subsequently becoming dislodged and discharged onto a following vehicle and causing damage to the vehicle or possibly resulting in loss of control of the vehicle by an object striking the windshield, causing serious vehicle damage as well as possible personal injury to the occupants of the vehicle.
In an effort to prevent such a scenario from taking place, state laws have been enacted that requires mud flaps on trucks to be of a certain size, located at a certain position relative to the rearmost wheels of the truck and extend vertically for a specified distance, the standard mud flap is twenty-four inches wide by thirty-six inches long. However, due to the adverse conditions that most commercial dump trucks operate under, most mud flaps seen on trucks are somewhat less than the required dimensions since they have been damaged in a variety of ways when the truck is used in backing up to either receive or discharge a load. Some of the instances where mud flaps are damaged due to entanglement with the rear wheels during operating in reverse include backing into an embankment where the mud flaps are forced under the rearmost wheels, operating in soft soil conditions where the wheels sink into the soft, muddy soil and the mud flaps become entangled or operating in reverse with various types of auxiliary equipment such as loading a road paver where the mud flaps are pulled into the revolving rollers causing serious damage to the mud flaps. In some instances where trucks are provided with retractable mud flaps, the rise of the bottom of the mud flap is insufficient, resulting in a loop of the mud flap near the bottom, whereby this loop becomes filled with load discharge and is torn from its mounting when the truck is pulled away. It is with this knowledge in mind that applicant has developed a mud flap retractor system that automatically becomes engaged when the driver of the truck places the transmission in reverse to begin backing up and is raised to a sufficient height whereby the above noted problems are eliminated.
A pre-examination search of the prior art was made by applicant and revealed the following patents.
U.S. Pat. No. 2,653,846xe2x80x94issued to G. D. Wiley on Sep. 29, 1953xe2x80x94discloses a rear wheel splash guard for a dump truck that is manually operated through the use of a plurality of interconnected linkages beginning with actuating lever 36 that activates a rigid splash guard and moves from a vertical position to a substantially horizontal position as shown in FIG. 1. This unit is not automatically operated as in the subject application and relates to a rigid splash guard rather than a pliable, flexible flap as presently in use on most trucks today.
U.S. Pat. No. 2,857,200xe2x80x94issued to G. Hoppesch on Oct. 21, 1958xe2x80x94discloses a rigid mud flap that is retractable by use of a hydraulic system that is tied in with the hydraulics of the vehicle in response to the dumping of a load during use. In this patent emphasis is placed on the fact that the mud flap is made of a rigid construction to prevent entanglement with the rear wheels during a dumping operation.
U.S. Pat. No. 2,872,211xe2x80x94issued to R. F. Barrett on Feb. 3, 1959xe2x80x94discloses a retractor system that is manually actuated through the use of a cable that rotates the guard from its normal rear wheel position to a position on the outboard side of the wheel during the dumping operation and is returned to its rearward position by a biasing spring. Here again, the operation is manual requiring the initiation of the retraction by the driver of the truck.
U.S. Pat. No. 3,248,126xe2x80x94issued to G. R. Saxton et al on Apr. 26, 1966xe2x80x94discloses a mud flap retractor system that is operated through a pneumatic cylinder that activates a member having a pair of cables attached thereto for retracting the flaps.
U.S. Pat. No. 3,310,344xe2x80x94issued to M. Beintum et al on Mar. 21, 1967xe2x80x94discloses a spring assisted system that operates through a series of rods to flip the mud flap to a horizontal position in preparation for the dumping operation.
U.S. Pat. No. 3,507,513xe2x80x94issued to A. H. Bohrer on Apr. 21, 1970xe2x80x94discloses a system utilizing a plurality of sprockets, rollers and a chain to retract the mud flap into a horizontal position within a frame mounted casing.
U.S. Pat. No. 3,580,604xe2x80x94issued to T. F. Overbend on May 25, 1971xe2x80x94discloses a mud flap assembly that utilizes a pair of vertically spaced parallel flaps on each side of the vehicle with a plurality of cantilevers that are spring biased in one direction whereby the outer flap is raised to a confronting position relative to the inner flap thus shortening its length to prevent engagement with any material present in the vicinity of the flaps.
U.S. Pat. No. 3,582,109xe2x80x94issued to V. Moore on Jun. 1, 2971xe2x80x94discloses a system wherein a cable is attached to each mud flap and operated by a single pneumatic cylinder that operates a pivotable lever arm to retract the cables and simultaneously retract the mud flaps.
U.S. Pat. No. 3,934,901xe2x80x94issued to R. C. Hammerly on Jan. 27, 1976xe2x80x94discloses a quick release mud flap hanger that requires manual removal of a detent connected hanger from its socket to prevent damage to the mud flap during dumping of a load.
U.S. Pat. No. 4,097,090xe2x80x94issued to C. Payne on Jun. 27, 1978xe2x80x94discloses a bracket mechanism that is attached to the tailgate and elevates the flaps while maintaining their vertical positions when an air cylinder is activated in preparation for dumping.
U.S. Pat. No. 5,582,431 issued to G. D. Anderson on Dec. 10, 1996xe2x80x94discloses a retractable mud flap that includes an enclosure for the mud flaps when they are retracted into a horizontal position by pneumatic or hydraulic cylinders.
U.S. Pat. No. 6,139,062xe2x80x94issued to D. Meyer on Oct. 31, 2000xe2x80x94discloses a pneumatic cylinder that operates a series of linkages including a C-shaped arm that swings in an operation arcuate path to engage the mud flap and raise it up sufficiently during a dumping.
U.S. Pat. No. 6,158,775xe2x80x94issued to D. R. Nickels on Dec. 12, 2000xe2x80x94discloses a system that includes a single power cylinder that operates a pair of cables that ride over a series of rollers and guide the cables when pressure is applied to the cylinder to retract the mud flaps.
As can be seen from a review of the above cited patents, many attempts have been made to come up with a mud flap system that satisfies the needs of the trucking industry. However, due to the complex, cumbersome arrangements of the prior art devices, there still remains a need for a mud flap retractor system that is easy to install, takes up a minimum amount of space, is readily accessible and is automatically energized once the driver of the truck places the transmission in reverse gear. None of the prior art devices disclose a housing for a plurality of cylinders that are located immediately above the mud flaps in a compact, easily accessible location that is mounted onto the housing frame for the mud flaps and provides a mounting for the rear lights of the vehicle. By means of this location in close proximity to the mud flaps, the length of the operating cables and the stroke of the operating cylinders is significantly reduced thus reducing the amount of space required as well significant reduction in the overall costs of the system.
The present invention provides an automatically activated mud flap system that is conveniently located in close proximity to the mud flaps and is readily adaptable to all trucks using standard sized mud flaps by using the mounting holes of the currently used mud flaps. The system utilizes a pair of double-acting power cylinders for each mud flap that are tied in with the vehicle""s electrical system and either the air or hydraulic systems found on all such vehicles thus ensuring release of the mud flaps upon completion of the dumping operation. The system is comprised of a separate housing for each of the pair of compact units that are readily attached to the presently available mounting frame used for suspending the mud flaps and includes the rear lights such as the brake light, back-up light and turn signals. The system further includes two power cylinders for each mud flap and cooperating pulleys to guide the cables during their lifting or releasing procedures. The cable attachment location is positioned sufficiently low on the mud flap whereby the mud flaps are raised one-half the length of the flap when retracted thus ensuring that there will not be any interfering low positioned loop contact during a dumping operation. Additionally, weights are provided for each mud flap to ensure rapid lowering of the mud flaps upon completion of a dumping operation.
An object of the invention is to provide an automatic mud flap retractor system for dump trucks.
A further object of the invention is to provide a mud flap retractor system that initiates engagement when the truck operator places the transmission in reverse gear.
A still further object of the invention is to provide a mud flap retractor system that includes a unique pulley arrangement wherein the required lift of the mud flaps is accommodated with a minimum amount of piston rod extension thus reducing the overall size and space requirements for the retractors.
A further object of the invention is to provide the mud flap retractor system in kit form to allow retro-fitting of currently used non-retractable mud flaps.
Yet another object of the invention is to provide a mud flap retractor system that utilizes double-acting power cylinders and weights for each mud flap thus ensuring release of the mud flaps into their down position by merely actuating a release button located in the cab of the vehicle.
These and other objects of the invention will become more apparent hereinafter. The instant invention will now be described with particular reference to the accompanying drawings wherein like reference characters designate like or corresponding parts throughout the several views.